What is Ankylosing Spondylitis?

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by pain and progressive stiffness. It mainly affects the spine, but other parts of the body can be affected as well. AS is part of a group of rheumatic diseases termed seronegative spondyloarthropathies. "Spondyloarthopathy" is the medical term for a disease that affects the vertebral joints.

In 1973, researchers discovered an association between ankylosing spondylitis and the antigen HLA-B27. An antigen is a protein that helps the body to make antibodies to fight infection. However, not everyone who has the HLA-B27 gene will develop ankylosing spondylitis; it is present in some people who do not have AS. However, an overwhelming number of people with AS (90%) have the HLA-B27 genetic marker, so there is some link between the gene and the disease.

AS affects white males about four times as often as females. Symptoms usually first occur between the ages of 15 and 45, and while there is no cure for ankylosing spondylitis, there are many treatment options available to help control the pain from the inflammation and spinal stiffness.

A solid understanding of your spinal anatomy will help you understand how ankylosing spondylitis (AS) affects your spine. Learn about the different spinal regions where AS can cause inflammation and fused bones.